[Malignant cystosarcoma phyllodes]

The authors deal with the clinical and pathological aspects and histopathological criteria of malignity of cystosarcoma which are important from the aspect of assessment of the extent and type of surgical intervention. Large malignant cystosarcomas and cystosarcomas taking up the whole breast with damage of the skin are indicated for simple mastectomy, while small malignant cystosarcomas (i. e. in relation to the size of the breast) can be treated by a wide local excision with a safety margin, as some primary as well as recurrent phylloid tumours behave in a benign way or may transform into a fibroadenoma or a dysplastic focus. Moreover contrary to carcinoma of the breast, there is no association with a multicentric character of the disease. Axillary lymph nodes are only rarely affected; therefore dissection of the nodes is not necessary.